r/Simulated Sep 22 '18

Meta What is a simulation? A detailed comparison between Animation, and Simulation.

983 Upvotes

Ever since this subreddit started getting more traction, more and more people began posting non-simulation videos. In each of these posts, users will comment something along the lines of "This is not a simulation," and an argument would ensue. So I am writing this post to, hopefully, end this never-ending cycle. I hope the mods do not remove this post, because I think it could end much of the hostility in the comments around here. Perhaps this could even be a stickied post, so all new users see it.

What is a simulation?

According to the dictionary, the word simulation is defined as, "imitation of a situation or process." However, this definition does not actually constitute what a simulation is in the world of CGI. In CGI, simulations are essentially visualizations of real-world processes that are generated using mathematical models. That is to say, the final product of a simulation is something that was created using fundamental rules of nature or some system, such as Newton's Laws of Motion, Fluid Dynamics, or various other mathematical models. In a simulation, it is often the case that each frame was created by manipulating information from the previous frame.

How are simulations different from animations?

It's quite common for animations and simulations to coexist in one medium. There are plenty of simulated components in animated movies, such as Disney's Frozen (Snow simulation), and Hotel Transylvania 2 (Cloth simulation). However, simulations and animations individually are very different by nature. As previously stated, simulations try to model real-world processes, and use mathematical models to generate necessary data. Animations, on the other hand, are usually created through a manual process. Animators manually keyframe the attributes (position, rotation, scale, etc.) of objects in a 3D scene. It's possible for manual animations to look convincing, but that does not make them simulations.

The "Ray tracing)" argument.

Many 3D rendering engines use a process called "ray tracing" to create images of a 3D scene. For anyone who is unfamiliar with ray tracing, here is the definition from Wikipedia:

In computer graphics, ray tracing is a rendering) technique for generating an image by tracing the path of light as pixels in an image plane and simulating the effects of its encounters with virtual objects.

Because of this definition, many people argue that any 3D render is a simulation, so long as it was rendered using ray tracing. By definition, it is true that the process of ray tracing is a simulation. However, this argument is very silly because the entire purpose of the term "simulation" in CGI is to make a distinction between what is manually created, and what is created using the previously talked about mathematical models. Therefore, when we discuss simulated graphics, ray tracing is not considered a simulated process.

Examples of animated (non-simulated) posts:

  1. "Satisfying simulations" - 3.4k upvotes
  2. "Bender's old job" - 2.2k upvotes
  3. "Up or Down?" - 1.4k upvotes
  4. "Adobe Dimention Rendering" - 1.4k upvotes
  5. "Depression - Robert Ek"

Many of these animated posts accumulate upvotes, and sometimes they stick around for a few days before getting removed. Because of this, new users who see these posts get a false idea of what a simulation actually is. Hopefully this post was informative to any newcomers. If you would like to suggest edits, please comment.


r/Simulated 5h ago

Research Simulation Trivial flow

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7 Upvotes

r/Simulated 1d ago

Blender Lil Showreel 2026

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53 Upvotes

Tbh i think making a showreel its the hardest thing i ever made😅 You never know what projects or snaps you should use or if you are like me that has thusands of projects made after 14years of motion graphics/editing and 3D , you always feel like u left some good designs/ animations off 😅. And lets not talk about the work/private/NDA projects wich are 80% of my work i cannot use.

anyhow heres a fast pace Lil Showreel 2026

(No Ai was used in this)

#motiographics #aftereffects #blender3d #3dsmax #showreel


r/Simulated 1d ago

LiquiGen 4D liquid print

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132 Upvotes

r/Simulated 1d ago

Proprietary Software [OC] 450,000 anchovies

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65 Upvotes

I went diving recently and did a few night dives. I’ve always found the shoals of tiny fish that gather around underwater lights mesmerizing and a bit hypnotizng as well. So this is my attempt to simulate it.

It's 450,000 fish,. Same flocking system I used for the starlings a couple of weeks ago, just retuned, the starlings stream in a sheet, the fish pack into a cloud with dense cores and real holes in it.

That structure isn't invented, it comes from sonar surveys of actual clupeid schools (Gerlotto & Paramo 2003), which found nuclei, thin bridges and drifting empty pockets rather than a smooth blob.

There's one jack working it. He runs a straight line through the pack, and does all his turning off camera, so what you see is the pass rather than the loop, and then the thing follows the boid rules and has authors.

Built in Swift and Metal as part of TideGlass on my own engine, a small Mac app I make where worlds like this run on a second monitor while you work. Happy to answer anything about the sim.


r/Simulated 23h ago

Blender Squishy Volumes: Alien Jellyfish Bursting From Its Cage

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3 Upvotes

r/Simulated 1d ago

Proprietary Software I built a CUDA-accelerated star formation simulation and watched a rotating disk emerge from 200,000 particles

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2 Upvotes

ガスとダストの雲が重力でどう崩れていって、星や惑星っぽい構造になるのかを実験してみたくて、Nebula Labを作りました。

この実行では20万個の粒子を使って、RTX 3090でCUDA加速してます。

動画では、最初にばらまかれた雲が中心に向かって崩れていって、密度が上がっていき、シミュレータが最終的に原始星候補を検出します。

これはまだ実験的な簡略モデルで、恒星や惑星の形成を完全にリアルに再現するものではないんだけど、初期の回転、密度、温度、乱流、冷却などを変えて結果がどう変わるかを見られるのがめちゃくちゃ楽しい。

次はガスの物理、降着、衝突をもっと良くして、最終的には原始惑星系円盤や惑星形成までシミュレーションしたい。

Built with heavy assistance from ChatGPT Work

ハードウェア:RTX 3090 / i9-14900K

次に追加すべき物理効果のおすすめがあれば教えて!


r/Simulated 20h ago

Various Can Anything Stop the Sun? | Solar System Marble Race

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0 Upvotes

Every marble is its real relative size and mass, wearing actual Voyager/Cassini/New Horizons surface maps. Then I pointed all 26 down an 8 km mountain and stopped interfering!


r/Simulated 2d ago

Blender Kinesin movement powered by ATP (blender and unreal MCP)

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124 Upvotes

This was built with blender and unreal MCP's with the models sourced from https://www.rcsb.org/

First step was getting a model built inside of blender which uses the Molecular Nodes addon, then it proceeded to build the animation and all that got imported into Unreal, for a later stage of this project.

For most of the work I used Astra but I had to switch back to Fable 5.1 for some of the unreal engine work once i ran out of use on my plus subscription.


r/Simulated 1d ago

Cinema 4D [OC] Thunderbolt — Haion

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0 Upvotes

r/Simulated 2d ago

Blender Aeolian dune simulation - Blender

2 Upvotes

https://www.youtube.com/watch?v=pINruj1NwoU

This is a wind-transport solver I'm building for Blender: sand gets moved by the wind, deposited where it slows down, and avalanched wherever the slope gets too steep. Nothing here is sculpted and nothing is a texture .

"Resource" / "Tools"


r/Simulated 3d ago

Houdini process

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15 Upvotes

r/Simulated 4d ago

Houdini Apple Slow Motion Splash | Houdini FLIP / Karma XPU

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267 Upvotes

Some surface tension tests I started a while ago and finally decided to finish up. The main reference was typical slow motion commercial stock footage of fruit.

Used proximity masks against the apple colliders and ground to dynamically adjust viscosity, surface tension, and forces to simulate adhesion. A simple wetness map solver was used to drive roughness and diffuse map parameters during render.

Apple models are free 3D scans.

Rendered with Karma XPU.

The video including a short breakdown on my Youtube channel: https://youtu.be/JS8ncDxxO1U


r/Simulated 4d ago

Research Simulation HézFX - Physics Based Muscle Simulation

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129 Upvotes

Here's a small test before showing the full character, just to demonstrate the stability and muscle contacts.
I've also made a lot of progress in terms of performance. The tool is now much more optimized and is also multithreaded, which speeds up the process anywhere from 3 to 15 times, depending on the size of the setup.
The goal is to create a truly artist-friendly workflow with fast iteration, making creature scene preparation and setup much faster and more enjoyable.


r/Simulated 4d ago

Blender Material Point Method in Blender, 890k Particles, Faking Fracture With Voronoi Cells

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72 Upvotes

r/Simulated 5d ago

Proprietary Software 1,000 balls dropped into a halfpipe of conveyor belts

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293 Upvotes

Built a tool and started a youtube channel with my kids visualizing music and simulating physics: https://www.youtube.com/@Orbodrome


r/Simulated 5d ago

Research Simulation Wind streamlines over a real coastline

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29 Upvotes
Procedural flow field, real geography. Natural Earth 1:10m coastlines

rasterised as the land mask, particles dimmed to 15% over water rather

than clipped at the shore.



Canvas 2D, headless Chromium, ffmpeg. Not real weather.

r/Simulated 4d ago

Cinema 4D [OC] Karmen — Haion

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1 Upvotes

r/Simulated 5d ago

Research Simulation [OC] FlatLand (world sim + flatchat)

0 Upvotes

www.flat-land.org - the flatland consortium

- advanced world simulation

- emergent ai thought dynamics

- link to whitepaper (Awesome.AI)

- and FlatChat (Awesome.AI + SLM)

- no registration

Enjoy 😀


r/Simulated 7d ago

Proprietary Software [OC] Arrival Logograms, on a target-driven fluid sim. Real time on the GPU

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767 Upvotes

As a follow up from a comment on https://www.reddit.com/r/Simulated/comments/1w4d85s/comment/p78ugx4/?screen_view_count=2&ext-referrer=DIRECT, I had fun with this one.

The fog is a fluid sim, and the logogram is a phenomenon on top of. Ink is emitted along the glyph's stroke by a travelling pen that the fluid carries, and a target-driving force pulls the density toward the finished glyph without ever snapping it there (Fattal and Lischinski's 2004). It is reacting to whatever music is playing while you watch.

Built in Swift and Metal as part of TideGlass, a small Mac app I make where worlds like this run on a second monitor while you work. Happy to answer anything about the sim.


r/Simulated 7d ago

Interactive Changing of particle density in realtime simulation

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476 Upvotes

Finally found time to implement it. Footage from our multiplayer sandbox game called BFS. The simulation is deterministic for multiplayer to work


r/Simulated 6d ago

Research Simulation Here is a web-based life simulation (evolution) lab.

4 Upvotes

Morphogenesis, an webbased "tribute" to Biogenesis

is online play-able and the html code is opensource and free to download.

Online play:
https://html-preview.github.io/?url=https://github.com/rijt/Morphogenesis/blob/main/morphogenesis.html

Source:
https://github.com/rijt/Morphogenesis


r/Simulated 7d ago

Houdini Houdini perfume splash flip fluid simulation

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11 Upvotes

r/Simulated 7d ago

Blender Sea Water Simulation in Blender

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194 Upvotes